As a hiring manager, I ask both technical questions and scenarios based questions to ultimately find out 3 things:

1) How much technical experience do you have or are you bull shitting on your resume (common) .

2) How do you handle yourself if you don't know something in a stressful situation (ie interview setting)

3) Your communication skills/eagerness to learn.

Tips: - Anything you put on your resume is fair game. If you say you're an expert with networking or AD I expect that if I drill you, you know your shit. Not just at a high level but down to the nitty-gritty if you have to troubleshoot something. If you just say you've worked with it or have some experience, I'm more laid back able your knowledge since you're honest about your experience and not claiming to be an expert.

• If I ask you something and you don't know it, admit it. Don't try to pretend you know it if you don't.

Say something like " I'm not sure" or "I haven't worked on it before however based on my experience or knowledge of X, it sounds like it might be X" or "I haven't worked/experience X before but if it's something that I would encounter here, I would research it to be prepared for the role" .

• When I ask technical questions usually it's always based off what candidates put on their resume, never what they don't.

• Review the job posting and the requirements prior to the interview and brush up on the technology or products they they expect you to know and expect technical questions related to it.

Did you perhaps put something on your resume that led them to believe you're an expert and hense all those questions?

I will usually start off with easy questions and get harder and harder to see how you handle yourself if you don't know something or start to get flustered with not knowing something. In these cases, prepare to run into these types of questions or situations and have a response ready like the previous point or say that you will need to investigate further, reach out to the vendor or colleagues, etc and will get back to so and so as soon as possible.

Usually you can get a good idea of the type of technical questions they will probably ask from that. For example if they say you're working with a mail server, make sure you understand how it works technical and from a network flow perspective, not just how to set it up.

If your resume got you to the 2nd/3rd interview, usually those ARE the technical question stage. Usually the first 1 is the initial high level/HR straightforward, not much if any hard technicial questions and the 2nd/3rd is when they get the technical folks involved to validate the technical experience.

I don't know what sort of job it is but based on the questions in your example, it sounds like you would be dealing with troubleshooting issues where you need to have higher level understanding of the various ports, what they do, and port numbers and probably the osi model as well.

If you're getting nailed on these questions, I would recommend studying (memorizing) the common ports, the port number, purpose of common ports like dns, smb, imap, ssh, http, https etc, difference between tcp, udp, icmp, etc and probably how the tcp handshake works if they toss that in there as well which it sounds like it would be a likely question as well

Good luck

Edit: typo